Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
6 Nov

Boxers or Briefs?

Boxers or Briefs?Believe it or not, it’s a question I get fairly often: “Grok didn’t wear tighty-whities. Should I?”

From time to time, I like to have some fun and expand the scope of this blog beyond the regular topics. Health and wellness, after all, come down to far more than just diet and exercise (and sleep and sun and stress, for that matter). So I’ve written about everything from the benefits of squat toiletsgoing poo-less, and stand-up workstations to the dangers of excessive sitting, nighttime light exposure, and passive living. Today, I’m going to branch out again. Today, I’ll attempt to answer what sages, wise men, gurus, and guys sitting around in gym locker rooms could not: boxers or briefs (or nothing at all)? So fill your cup and let’s dig in.

This topic was prompted by a reader’s email:

I thought this could be an entertaining topic.

We’ve all seen the Seinfeld episode where Kramer starts wearing boxers when Elaine tells him boxers are better for his sperm count.

Is there any hormonal drawbacks associated with briefs that could be caused by the low sperm count or vice versa?

Our ancestors were certainly “out there, and loving every minute of it.”


Here’s the Seinfeld clip in question:

Having watched that, I’m not even sure a post is necessary. Kramer pretty much covers it. Still, not everyone has access to YouTube at work, so I’ll continue.

I’m not going to discuss the subjective effects of wearing boxers, briefs, or nothing at all. People have their preferences. Some people like providing a safe, secure, snug house for their boys, while others take a more free-range approach. No value judgements cast here.

But what’s our natural state?

While it could be argued that going commando is “most natural,” seeing as how we’re all born in the Hanes-less state, I’d say that loose-fitting boxers are pretty close to natural, too. Loincloths were the earliest undergarments, and those were essentially just a piece of fabric loosely looped between the legs. Plenty of air flow and very little confinement. Grok’s private bits definitely breathed, whether he wore a loincloth or nothing. Okay, so one is more natural than the other(s), but does that make a difference for our health? Natural doesn’t always mean better, you know.

“Everyone knows” that wearing tight briefs reduces sperm count, and I briefly discussed this in a Dear Mark that asked about laptops and infertility. It’s true that scrotal heat stress does have the potential to affect sperm quality, count, and motility, as in men with varioceles – enlarged testicular veins that lead to excessive blood flow, elevated scrotal temperatures, and sometimes infertility – but it’s unclear whether choice of underwear represents a significant-enough thermal stress to the scrotum to induce negative changes. The questions we must ask are: does the choice of underwear truly affect scrotal temperatures? And if it does, is it sufficient to negatively affect male fertility? Let’s look at the evidence:

In one study, healthy young men wearing tight-fitting polyester-lined athletic support garments consistently displayed elevated scrotal temperatures between 0.8 and 1 degree C. This increase, however, did not affect any fertility parameters, including sperm concentration, sperm motility, sperm morphology, sperm viability, sperm hyperactivation, and the ability of sperm to penetrate hamster oocytes (sadly, no hamster-human hybrids were created throughout the course of this study).

Another study found no difference in scrotal temperatures between wearers of boxers and wears of briefs. In fact, the average temperature was actually a hair lower in the brief group, though it wasn’t significant. Fertility parameters all checked out, as well.

In another study, the author measured how various garments and positions affected his own scrotal temperature. Boxers were 0.5 degrees C cooler than briefs. Scrotal slit underpants were 1.2 degrees cooler than boxers. Sitting with thighs apart was 1.6 degrees cooler than sitting with thighs together. He didn’t measure his fertility parameters, however, so we don’t know whether or not those were affected.

And finally, a team of researchers studied the effects of boxers, briefs, and going commando on the scrotal temperatures of 50 healthy men without a history of infertility. They found conclusive evidence that wearing tight-fitting underwear such as briefs resulted in elevated scrotal temperatures, though it “remains to be elucidated whether these differences are linked to semen quality and consequently male fertility.”

Choice of fabric might make a difference, too. In an Egyptian study, one researcher used polyester slings (that allowed penis exposure but kept the scrotum confined) to induce azoospermia – the state of having no measurable sperm in semen – in previously fertile men. These were like briefs on steroids, fully preventing the tendency of the scrotum to “hang low” (which it does for thermoregulatory purposes). They caused the testicular temperatures to approach the rectal temperatures, which is way hotter than testicles are built to withstand and which apparently contributed to the infertility. But the author also thought that scrotal-polyester friction-induced electrostatic charges might have played a role as well. To figure out which was responsible, that same researcher did a followup study, this time using dogs in specially-fitted underwear. To eliminate the confounder of scrotal temperature, he made the underwear loose fitting. And sure enough, testicular temperature didn’t change much. Not even in the polyester group. The dogs wore the underwear for 12 months straight. Once again, the polyester underpants killed fertility (without affecting temperature), while cotton underwear dogs and control dogs (commando) experienced no change. I was alive during the seventies, and I can certainly vouch for the friction that occurs between bare skin and polyester.

As for the hormonal stuff? While scrotal temperature changes do affect follicle stimulating hormone, which controls sperm quality and count, they do not seem to affect testosterone levels. Fertility can be affected, but not via testosterone.

I wish I could give you an absolute proclamation, here, but I can’t. How about some general guidance?

  • If you’re having trouble conceiving, or your sperm count comes back low, and you wear briefs or some other tight-fitting underwear, switching to boxers, or cotton, or nothing at all might help. Either way, it’s not going to hurt.
  • Normal scrotal temperature – the kind that promotes fertility – is one or two degrees C below body temperature. As seen in the Egyptian study, once the scrotal temperature approached the rectal (body) temperature, fertility was impaired. The best way to measure your scrotal temperature is with an infrared thermometer, which can be a bit pricey.
  • Don’t wear tight fitting underwear – polyester or not – for 12 months straight. Give your boys some time off, whether that comes through targeted ice baths, walking around (walking and standing and even running lead to cooler scrotums than sitting) more, or switching to more forgiving undergarments.
  • Switch to a natural fabric, whether it’s cotton, animal skin, or nothing.
  • Don’t be in such a rush to always replace your underwear with a gaping hole in the crotch. It might actually be helping, especially if it facilitates scrotal drooping.

Thus, as is usually the case, there’s no right or wrong answer here. While wearing tight-fitting briefs can increase scrotal temperature, which can affect fertility, it’s not a sure thing. The research is unclear, and the ultimate choice rests in your hands. Go ahead and mess around with infrared thermometers if you’re really concerned, and get your sperm count tested, but you probably don’t have much to worry about as long as you’re adhering to the general guidelines listed above.

So, dear readers, what say you – boxers or briefs?

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Lightweight cotton or something moisture wicking for the underwear — and try looser fitting pants instead of all the silly skinny jeans styles.
    Tropical weight wool trousers for hot weather instead of blue jeans. Wool can be incredibly fine and much better for temperature control.

    And I like the switching-it-up ideas. Briefs for activity, boxers to sleep.

    Oly wrote on November 6th, 2012
  2. Obesity inhibits cooling in the pampiniform plexus (testes radiators), and thus inhibits testosterone production AND sperm motility. Tight undies do the same thing.

    Derek wrote on November 6th, 2012
  3. Wow! I’ve laughed out loud at several points on today’s topic. Thanks everyone!

    I’m also reminded of an episode of Friends (Season 3) where Phoebe’s new boyfriend wears shorts all the time . . . and goes commando under them.

    W.J. Purifoy wrote on November 6th, 2012
    • “This is a family place, mister. Keep the mouse in the house.”

      Sari wrote on November 13th, 2012
  4. Whoa there, boys! Did someone just come up with non-hormonal and non-invasive male birth control … underwear? Yay!!

    Saara wrote on November 6th, 2012
  5. Congrats Mark on having the balls to tackle this hot topic. I was inspired by the comments of women wearing men’s underwear to bed, so tonight I am going to try some of my wife’s. Hum, panties, thong or crotchless? I am feeling free.

    andre Chimene wrote on November 6th, 2012
  6. I am so going to go around all day looking for opportunities to use the phrase “scrotal drooping”

    Chance Bunger wrote on November 7th, 2012
  7. I’ve worn tight-fitting briefs all my life. When it came time for us to have children, the first of which came when I was 37, all I pretty much had to do was sneeze next to my wife when she was ovulating and she got pregnant, first try.

    Did this issue of infertility come about with tight briefs? Heck no. It came about with the increasing use of soy in our diets, along with other estrogenic influences in our lives, not to mention the complete chemicallization of our lives.

    Joe Carbup wrote on November 7th, 2012
  8. A lady at a church meeting was asking me for details on my Primal weight loss. We were interrupted before I could give her the marksdailyapple web address. This would have been the first entry that she read! She’s over 60 and very prim and proper. Imagining her response is almost as funny as that Seinfeld clip.

    Kathy wrote on November 7th, 2012
  9. I wear athletic polyester compression shorts. I got this from when I used to go hiking a lot. Cotton soaks up water and doesn’t dry or breathe as well as polyester.

    Nathan wrote on November 7th, 2012
  10. Having spent the better part of the summer in Afghanistan, I am sold on merino wool undergarments.

    Boxerbriefs, undershirt and socks are all merino wool. It’s pricey, but holy hell is it comfortable, breathable, non-chafing, odor resistant, and flame resistant.

    I highly recommend checking out Smartwool or Icebreaker.

    Seph wrote on November 8th, 2012
    • Hi there,
      I do promotion for wool in South Africa and was send your comment by a friend. Would love to know more about your wool experience and send it out on a newsletter, if you are keen?

      Nothing like wool against the skin, but people do not believe it until they experience it…

      Kind regards
      Dalena White

      Dalena White wrote on November 8th, 2012
  11. I’ve gone commando for several years now and never regretted it for a minute. I do lots of running, hill sprints, and pretty much every conceivable (functional) exercise in the gym. Never had a problem. I was a bit worried the first time I did lunges and hand stand push ups with nothing but a loose fitting pair of gym shorts between me and a count of misdemeanor public exposure. Never had an issue with that or with any kind of bruising or chafing, which used to be a huge problem for me.

    I highly recommend giving it a whirl.

    Nic wrote on November 8th, 2012
  12. “Scrotal heat”… awesome band name.

    Trav wrote on November 8th, 2012
  13. I recommend accustoming yourself to variety. My husband absolutely refused ever to wear anything but boxers. When his illness started to result in occasional bowel incontinence, the mess was awful. I finally asked advice from other men (on Facebook!) and insisted he try boxer briefs, which he decided were ok. Except he had an issue with the fly being too hard to use, so I had to cut one layer of fabric. I discovered that today the big divide isn’t between boxers or briefs but between men who use the fly (leaving the button and belt fastened) and those who don’t.

    Pamsc wrote on November 8th, 2012
  14. As a female, I have to object to this statement:

    “Don’t be in such a rush to always replace your underwear with a gaping hole in the crotch. It might actually be helping, especially if it facilitates scrotal drooping.”

    I guarantee this will not help your chances of procreation.

    Darya wrote on November 9th, 2012
  15. This post seems as good a place as any to spam this humorous George Washington song. It’s fairly primal.

    Animanarchy wrote on November 9th, 2012
  16. I have never liked wearing any underwear as early as I can remember,because I have always found them uncomfortable. They always tended to bunch up, get stuck up my ass crack or cause me to sweat too much. Through the years, I have tried just about every kind of undergarment from time to time, and I still prefer to go commando. So, I have been 100% commando for about 20 years.

    Jim wrote on November 21st, 2012
  17. As a child I used to wear briefs then I switched to boxers when I was 13 or 14. In college I started to wear boxer-briefs. Now I’m switching back to briefs. I feel more comfortable wearing tight underwear

    Mike wrote on January 12th, 2013
  18. For the last sixteen years I have been a tour operator.As such, I drive considerable distances, and often in warm to hot areas.About fourteen years ago I started to develop heat rashes in the groin area.At the tine I was being by a dermatologist for another problem.I mentioned my heat rashes to her,(yes a lady doctor).The doctor told me that my problem was common, particularly with those who spent much time driving in warm to hot areas.
    Her words to me were:’Allow as much air circulation as possible in the groin area’.When I next visited her, she asked about the heat rashes (She is a relatively youngish lady with a good sense of humour), I told her they were gone.She then asked if I had followed her advice completely to which I replied ‘Yes’.
    That my story with underpants.Incidentally I am meticulous about hygiene

    Peter wrote on August 1st, 2013
  19. Boxer briefs–my boys need a house, but a roomy, well-ventilated house. :)

    Kent H wrote on November 4th, 2013
  20. The only time I wear something tight is when I go running. My doc suggested I use a jock strap after I had a bout with epididymitis years ago, and I never went back. Things are good down there now. I also have been using a penis health creme that contains Vitamins B5, C and D. All of these vitamins are awesome for blood circulation and penis health in particular. You guys should look into it. Cheers.

    Michael Harrington wrote on May 27th, 2015

Leave a Reply

If you'd like to add an avatar to all of your comments click here!

© 2016 Mark's Daily Apple

Subscribe to the Newsletter and Get a Free Copy
of Mark Sisson's Fitness eBook and more!